JP4139285B2 - Carrier for developing electrostatic image - Google Patents

Description

  The present invention relates to a carrier for developing an electrostatic latent image and a developer including the carrier.

In recent years, printing apparatuses using an electrophotographic system have been rapidly colorized and the printing speed has been increased.
Conventionally, the two-component development method is suitable for high-speed printing and has been widely used in full-color image forming apparatuses because non-magnetic toner is easy to handle. However, the full-color printing apparatus needs to have a plurality of developing devices in the apparatus, and there are drawbacks such as an increase in the size and weight of the apparatus as compared with a monochrome machine. In particular, the two-component developing device needs to have a developer storage volume and its stirring mechanism separately from the toner as compared with the one-component developing device. In order to reduce the size of the developing unit, a small amount of developer is required. It was essential.

  The carrier in the developer is repeatedly subjected to mechanical friction and impact in the developing device by friction with toner, a rubbing member such as a sleeve and a blade, a regulating member and a stirring and conveying member such as a screw and paddle. Decreasing the amount of developer means an increase in the chance of friction between the toner and the carrier per the number of printed sheets and an increase in the frequency of the carrier passing through the developing portion. As a result, the fatigue of the carrier in the developing unit rapidly proceeds. . Combined with higher printing speed, the carrier durability, especially high wear resistance of the film on the surface of the carrier, and contamination of the carrier surface due to toner and other components (spent) can be prevented and charging can be performed quickly over a long period of time. Maintaining gender has become more important than ever.

  In recent digital copying machines and printers, negative-positive development is often performed using a negatively charged photoconductor, and negatively charged toner is often used. Many examples are known in which a carrier film contains an organic compound containing nitrogen to negatively charge the toner. For example, there are an example in which an aminosilane coupling agent is mixed with a silicone resin, an example in which a certain kind of acid amide is internally added, a method in which an amino compound such as melamine or guanamine or a derivative thereof is internally added.

As an example in which such a nitrogen-containing organic material is used as a coating material, an example in which polyamide is conventionally used is disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 49-115549).
However, polyamide resins typified by nylon are generally preferable materials for imparting negative chargeability to toners, but many of them are poor in solvent solubility, so that a layer is formed by a simple method such as applying a solution. There are also problems such as difficulty in wear and insufficient wear resistance of the polyamide itself.

  In view of this, as examples in which polyamide is used after being solubilized in a solvent, examples in which a hydrogen atom of an amide bond is alkoxyalkylated are used in Patent Document 2 (JP-A-1-118150) and Patent Document 3 (JP-A-1-118151). ), Patent Document 4 (Japanese Patent Laid-Open No. 4-188160), Patent Document 5 (Japanese Patent Laid-Open No. 2001-201894), Patent Document 6 (Japanese Patent No. 3043390), and graft polymers having such a polyamide in the main chain. Examples of use are disclosed in Patent Document 7 (Patent No. 2835971) and Patent Document 8 (Patent No. 2835972). A film using such a polyamide as a main component is used in the abrasion resistance of the film. It was not enough.

Patent Document 9 (Patent No. 0923192) discloses that N-methoxymethylated polyamide is contained and the surface resistance is 13 or less. By partially methoxymethylating the polyamide, Although it has been shown that the film resistance is lowered, the lower resistance of the carrier due to residual methoxy groups is brought about by the high water affinity of the methoxy groups, and the environmental variability of the charge amount, the developer charge amount There was a problem such as a large decrease in storage.
JP-A-49-115549 JP-A-1-118150 JP-A-1-118151 Japanese Patent Laid-Open No. 4-188160 JP 2001-201894 A Japanese Patent No. 3434390 Japanese Patent No. 2835971 Japanese Patent No. 2835972 Japanese Patent No. 2932192

An object of the present invention is to solve the above problems.
That is, to provide a carrier that has a stable charge imparting ability over a long period of time and has excellent abrasion resistance of the film, to provide a carrier that is free from charge fluctuations due to spent toner composition, An object of the present invention is to provide a carrier that suppresses variability and a decrease in the amount of left charging, and is free from inconveniences such as image density fluctuations, background stains, and in-machine contamination due to toner even in various use environments.

  As a result of intensive studies, the inventors of the present invention have achieved excellent positive charging of polyamide by coating a carrier with a condensate of N-alkoxyalkylated polyamide and a silicone resin having a hydrolyzable group and a metal cross-linked product thereof. And the excellent spent property of silicone resin, and the film that cross-links them with each other, it is possible to improve the affinity with silicone and the cross-linking density of the film without impairing the chargeability of the polyamide. The present inventors have found that the wear resistance can be improved and have reached the present invention.

That is, the present invention
(1) One type having a form having a film on the surface of a magnetic fine powder, the film comprising (i) an N-alkoxyalkylated polyamide , and (ii) a silicone resin having at least a hydrolyzable group A carrier for developing an electrostatic latent image, comprising: a resin capable of reacting with the above alkoxyalkylated nitrogen-containing resin; and (iii) a crosslinked condensate formed from a coating solution containing a metal alkoxide.
(2) The carrier for developing an electrostatic latent image according to (1), wherein the polyamide of the nitrogen-containing resin is N-methoxymethylated polyamide having a methoxylation rate of 20% to 70%,
(3) The electrostatic latent image according to (1), wherein the film is a cross-linked resin formed of a coating solution comprising a mixture of silicone containing silanol, N-methoxymethylated polyamide, and aluminum alkoxide. Development carrier,
(4) The electrostatic latent image developing carrier according to (3), wherein the aluminum alkoxide is aluminum triisopropoxide,
(5) The carrier for developing an electrostatic latent image according to the above (3), wherein the aluminum alkoxide is aluminum trisec-butoxide,
(6) The carrier for electrostatic latent image development according to any one of (1) to (5), wherein the coating liquid contains a solid organic acid having a boiling point of 100 ° C. or higher,
(7) The carrier for electrostatic latent image development according to any one of (1) to (6), wherein the coating liquid has methylol melamine,
(8) The electrostatic latent image developing carrier according to any one of (1) to (6), wherein the coating liquid has methylol benzoguanamine,
(9) The electrostatic capacity according to any one of (1) to (8), wherein LogR at an applied electric field of 50 V / mm is 14 or more and a resistance value at 250 V / mm is LogR16 or less. A carrier for developing a latent image,
(10) The electrostatic latent image developing carrier as described in any one of (1) to (9) above, wherein the coating liquid contains a low-resistance substance.
(11) The electrostatic latent image developing carrier according to (10), wherein the low-resistance substance is conductive carbon,
(12) The carrier for developing an electrostatic latent image according to any one of (1) to (11), wherein the film has hard fine particles.
(13) The electrostatic latent image developing carrier according to (12), wherein the hard fine particles of the film are any metal oxide of Si, Ti, and Al,
(14) The electrostatic latent image developing carrier according to (13), wherein the content of the metal oxide particles in the coating is in the range of 5% to 70% of the coating weight,
(15) The electrostatic latent image developing carrier according to any one of (1) to (14) above, wherein the coating liquid contains an aminosilane compound.
(16) An electrostatic latent image developer comprising the electrostatic latent image developing carrier according to any one of (1) to (15) and an electrostatic latent image developing toner,
(17) The photosensitive member, a charging brush for charging the surface of the photosensitive member, and the electrostatic latent image formed on the surface of the photosensitive member are developed using the electrostatic latent image developer described in (16). A process cartridge comprising a developing unit and a blade for wiping off the developer remaining on the surface of the photoreceptor;
About.

As described above, according to the present invention, a carrier having excellent film strength and charge amount stability can be provided.
In addition, it is possible to provide a carrier with less spent derived from the toner composition.

Embodiments of the present invention will be described below.
The alkoxyalkylated polyamides used in the present invention, the amide bond of the hydrogen atoms in the main chain and alkoxyalkylated, using a solvent-solubilizing polyamide, a lower alcohol solution of the polyamide, the reactivity with the polyamide A coating solution prepared by mixing and dissolving one or a plurality of resins having a catalyst that promotes crosslinking as necessary is applied to a carrier core material having magnetism, dried, and heat-cured to form a film. The term “polyamide” as used herein refers to a general polyamide obtained from a dicarboxylic acid and a diamine, or a polyamide formed by ring-opening condensation polymerization of various lactams.
The alkoxyalkylation is preferably alkoxymethylation, more preferably alkoxymethylation in which the alkoxy group has 1 to 4 carbon atoms.

  For example, a method for methoxymethylation of polyamide is carried out by dissolving a polyamide such as formic acid and reacting with formalin in an acidic atmosphere in the presence of a lower alcohol such as methanol. Since the methoxymethylated polyamide thus obtained has improved solubility in lower alcohols such as methanol according to the reaction ratio, it is easy to form a film on the carrier surface.

  In addition, the polyamide exhibits rubber elasticity in an uncrosslinked state, and is heated in the presence of an appropriate acid catalyst to condense between the self methoxy group and the active hydrogen of the amide bond of the main chain, Crosslink and increase hardness. This is mixed with silanol-condensable silicone, applied as a carrier film, and heated in the presence of an acid catalyst to form a film having a cross-linked structure between silicone and polyamide.

Furthermore, it is possible to improve the wear resistance of the film by forming a film obtained by metal-crosslinking a part of the cross-linked resin between the polyamide and silicone.
As an example of metal cross-linking of the film, for example, it is carried out as follows. A non-aqueous solution such as a metal alkoxide is added to the N-methoxymethylated polyamide resin solution previously dissolved in a lower alcohol. If necessary, the pH of the solvent is adjusted using an organic acid, and the resulting solution and the silicone resin solution are mixed. This solution is applied to a magnetic powder as a core material of a carrier, dried, and heated to 100 ° C. or higher to crosslink and cure the film. The temperature required for curing depends on the resin used and the pH of the resin solution, but is 100 ° C. to 400 ° C., preferably 150 ° C. to 250 ° C., and the heating time is preferably in the range of 30 minutes to 3 hours.

As an example of the metal alkoxide to be used, alkoxides such as aluminum, titanium, tin, and zinc are preferably used. Among them, aluminum alkoxides are preferably used because they provide excellent charge stability over time and film strength.
As an example of the aluminum alkoxide, any alkoxide can be used, but typically, aluminum triisopropylate, aluminum trisec-butoxide, monosec-butoxyaluminum diisopropylate, aluminum triethoxide and the like are used.

  Examples of polyamides used in the present invention include, for example, 1,6 hexanediamine, 1,8 octadiamine, 1,2-propanediamine and other linear alkyldiamines, branched alkyldiamines, m-phenylenediamines, and the like as diamines. Examples of aromatic diamines and carboxylic acids such as p-phenylenediamine, o-phenylenediamine, toluene-2,5-diamine, N-phenyl-p-phenyldiamine, and 4,4-diaminodiphenylamine include maleic acid and fumar. Acid, mesaconic acid, citraconic acid, terephthalic acid, isophthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, dodecanoic acid, malonic acid, and other polyhydric fatty acids, aromatic dicarboxylic acids, and various amino acids Polymer, co-polymer consisting of several kinds of monomers Body, The amino acid of the self-condensation polymers such as ring-opening polycondensation or aminoundecanoic acid various caprolactam, and the like thereof mutual copolymers.

  The alkylalkoxylation treatment for solubilizing the polyamide is preferably about 20 to 70 mol% in terms of the substitution rate of active hydrogen of the amide bond. If the amount is less than this, the alcohol solubility is poor, and there are problems such as precipitation during film formation and segregation after film formation.

  The resin that can react with the alkylalkoxylated polyamide resin used in the present invention has alcohol, alkylol, carboxylic acid, amino group having active hydrogen, etc. having condensation reactivity with the methoxy group in the polyamide. Refers to all resins. Typically, a thermosetting resin is used. Among them, the silicone resin is preferably used because it has the effect of suppressing the so-called spent property that the toner adheres to and fouls the carrier because the surface strength of the resulting film is low as well as the film strength. As the silicone to be used, all silicone resins having silanol groups are used. Along with the crosslinking between the silanol group and the methoxy group of the polyamide by heating, an ester with an organic acid used as a catalyst for the polyamide is generated, and the negative polarity due to the remaining acid catalyst is suppressed.

  The silicone resin used in combination with the polyamide is a polymer having Si—O as a basic repeating unit, and includes a silicone resin containing a repeating unit represented by the following general formula.

（式中、Ｒは水素原子、ハロゲン原子、ヒドロキシ基、メトキシ基またはＣ１〜Ｃ４の低級アルキル基またはフェニル基を表わす。）

(In the formula, R represents a hydrogen atom, a halogen atom, a hydroxy group, a methoxy group, a C1-C4 lower alkyl group or a phenyl group.)

  Examples of such silicone resins include straight silicone, KR271, KR272, KR282, KR252, KR255, KR152 (manufactured by Shin-Etsu Chemical Co., Ltd.), SR2400, SR2406 (manufactured by Toray Dow Corning Silicone), and some of them are organic There are compounds, modified silicones obtained by substitution and addition, and examples thereof include epoxy-modified silicone, acrylic-modified silicone, phenol-modified silicone, urethane-modified silicone, polyester-modified silicone, alkyd-modified silicone and the like. Examples include epoxy modification: ES-1001N, acrylic modification: KR-5208, polyester modification: KR-5203, alkyd modification: KR-206, urethane modification: KR-305 (manufactured by Shin-Etsu Chemical Co., Ltd.), epoxy modification: SR2115, alkyd modification: SR2110 (manufactured by Toray Dow Corning Silicone) and the like are typical.

  In order to sufficiently cure the film, it is preferable to heat under an acidic condition, but as an acid catalyst to be used, it is preferable to contain an organic solid acid in the coating agent solution. When the boiling point of the catalyst is 100 ° C. or lower, the catalyst is evaporated at the time of drying the film, and the film cannot be sufficiently cured by the additional heat for forming the crosslink. Of these, polybasic carboxylic acid compounds having a dibasic acid or higher are preferably used. Examples of acid catalysts include lactic acid, lauric acid, crotonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, oxalic acid, succinic acid, glycolic acid, malonic acid, maleic acid, itaconic acid , Representative organic acids such as tartaric acid, benzoic acid, phthalic acid, trimellitic acid, benzyl sulfonic acid, toluene sulfonic acid, inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, hypophosphorous acid, etc. Although it can be used, in order to appropriately promote the previous crosslinking reaction, it is sufficient to select one having at least one boiling point of 100 ° C. or more as the acid catalyst.

For the purpose of controlling the charge amount of the film and improving the film strength, it is possible to mix other crosslinkable resins having reactivity with the alkoxyalkylated polyamide resin in addition to the silicone resin. Among these, various alkylol melamines and their derivatives, represented by hexamethylol melamine and tetramethylol benzoguanamine, are preferably used because they can provide film strength and high charge amount at the same time. Since the alkoxyalkylated polyamide used in the present invention has a low electrical resistance in the non-crosslinked state, there are problems such as background stains during image formation, a decrease in the charge amount of the developer, and a change in the charge amount due to temperature and humidity. It is necessary to sufficiently decompose the remaining methoxy component by a heating step for forming a crosslinked structure with the silicone resin. The electrical resistance of the carrier thus obtained is such that the LogR at 50 V / mm is 14 or more and 17 or less, and the resistance value at 250 V / mm is a range where LogR is 8 or more and 16 or less. When the electrical resistance value at 50 V / mm is 14 or less, the charge amount at the time of leaving is large, and the variation of the charge amount due to temperature and humidity is large. Further, when the resistance value at 250 V / mm is LogR16 or more, the image density is lowered due to charge-up of the carrier during continuous printing, which is not preferable.

In order to make the electric resistance of the carrier appropriate, it is possible to contain a conductive substance in the carrier film. As the conductive substance here, a known conductive material can be used. Examples of the conductive material, for example, conductive ZnO, metal powder such as Al, SnO ₂ doped with SnO ₂ and various elements made by various methods, borides, eg _{TlB 2,} ZnB _2, MoB 2 , Silicon carbide and conductive polymers (polyacetylene, polyparaphenylene, poly (para-phenylene sulfide), polypyrrole), etc., and most preferably conductive carbon black.

  Among these, carbon black is preferably used because a resistance value can be obtained over a wide range. For the purpose of reinforcing the film, other hard fine particles can be contained in the film. Among these, metal oxide and inorganic oxide particles are preferably used because they have a uniform particle size, high affinity with polyamide as a component of the film, and a remarkable effect of reinforcing the film. As such fine particles, conventionally known materials can be used alone or in combination, and typically include silica, titanium oxide, alumina, tin oxide and the like.

  Among these, alumina particles are preferable for imparting positive chargeability to the carrier. The content of hard fine particles contained in the film is preferably 5% to 70%, more preferably 2 to 40%. The content is appropriately selected depending on the particle diameter and specific surface area of the fine particles to be used. However, if the content is less than 5%, the wear resistance effect of the film is hardly exhibited, and if it exceeds 70%, the fine particles are easily detached. In order to adjust the charge level of the carrier, a silane compound having an amino group can be contained in the coating solution. Examples of the silane compound having an amino group herein include compounds represented by the following structure.

X-Si (OR) n
(Wherein, n is an integer of 1 to 3, X is a reactive or adsorptive functional group with an organic or inorganic substance, and a saturated or unsaturated hydrocarbon chain having a functional group, OR is Means an alkoxy group.)
Examples of preferable compounds include the following.

A conventionally well-known thing can be used as a carrier core material which provides a membrane | film | coat. Examples thereof include ferromagnetic materials such as iron and cobalt, magnetite, hematite, Li-based ferrite, Mn—Zn-based ferrite, Cu—Zn-based ferrite, Ni—Zn-based ferrite, and Ba ferrite. As the carrier core material, the above-mentioned magnetic particles are generally used, but a so-called resin-dispersed carrier having a form in which a magnetic powder having a smaller particle diameter is dispersed in a known resin such as a phenol resin, an acrylic resin, or a polyester resin is also suitable. Used.
As a method for forming the coating resin, a known method such as a spray drying method, a dipping method, or a powder coating method can be used.

The developer of the present invention consists essentially of the carrier and toner of the present invention.
The toner used in the developer of the present invention is mainly composed of a thermoplastic resin as a binder resin, and contains a colorant, fine particles, a charge control agent, a release agent and the like. In addition, toners produced by various toner production methods such as generally known pulverization methods and polymerization methods can be used.

  As binder resin, styrene such as polystyrene and polyvinyltoluene and homopolymers thereof, styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-acrylic acid Methyl copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer Polymer, styrene-o-chloromethyl acrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isobutylene Copolymer, styrene-maleic acid Polymer, styrene copolymer such as styrene-maleic acid ester copolymer, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, epoxy resin, polyvinyl butyral, poly Acrylic resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or aromatic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax and the like can be used alone or in combination.

  The polyester resin is obtained by a polycondensation reaction between an alcohol and an acid. Examples of the alcohol include polyethylene glycol, diethyl glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4- Diols such as propylene glycol, neopentyl glycol, 1,4-butenediol, 1,4-bis (hydroxymethyl) cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropylenated bisphenol A Etherified bisphenols such as these, divalent alcohol monomers in which these are substituted with a saturated or unsaturated hydrocarbon group having 3 to 22 carbon atoms, other divalent alcohol monomers, sorbitol, 1, 2, 3, -Hexanetetrol, 1,4-sarbitane, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol And trihydric or higher alcohol monomers such as 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane and 1,3,5-trihydroxymethylbenzene.

  Examples of the carboxylic acid used to obtain the polyester resin include monocarboxylic acids such as palmitic acid, stearic acid, and oleic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, terephthalic acid, cyclohexanedicarboxylic acid, and succinic acid. Acids, adipic acid, sebacic acid, malonic acid, divalent organic acid monomers in which these are substituted with saturated or unsaturated hydrocarbon groups having 3 to 22 carbon atoms, anhydrides of these acids, lower alkyl esters and Dimer from linolenic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1, 2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxylic acid-2-methyl A trivalent or higher polyvalent carboxylic acid monomer such as 2-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid embol trimer, and anhydrides of these acids; Can be mentioned.

  Further, examples of the epoxy resin include a polycondensate of bisphenol A and epichlorohydrin. For example, Epomic R362, R364, R365, R366, R367, R369 (manufactured by Mitsui Petrochemical Co., Ltd.), Epototo YD-011, YD- There are commercially available products such as 014, YD-904, YD-017 (manufactured by Tohto Kasei Co., Ltd.) and Epocoat 1002, 1004, 1007 (manufactured by Shell Chemical Co., Ltd.).

  Colorants include carbon black, lamp black, iron black, ultramarine, nigrosine dye, aniline blue, phthalocyanine blue, Hansa Yellow G, rhodamine 6G lake, calco oil blue, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallyl. Any conventionally known dyes and pigments such as methane dyes, monoazo dyes, disazo dyes, and dyes can be used alone or in combination.

  Further, the toner does not have any inconvenience even if it contains a drug to be contained for the purpose of controlling the triboelectric chargeability as in the case of the toner that is usually used. As such so-called polarity control agents, for example, metal complexes of monoazo dyes, nitrohumic acid and its salts, metal complexes of salicylic acid, naphthoic acid, dicarboxylic acid such as Co, Cr, Fe, etc. can be used alone or in combination. However, it is not limited to these. The polarity control agent used in the colorless toner needs to be colorless, and a polymer type polarity control substance having polarity is preferably used.

  A fluidity modifier can be added to the toner used in the present invention. Examples of fluidity modifiers include organic resin fine particles, metal soaps, Teflon (registered trademark), lubricants such as zinc stearate, abrasives such as acid value cerium, silicon carbide, etc. Known metal oxides used for the purpose, typically, metal oxide fine particles such as silicon oxide, titanium oxide, and aluminum oxide, and particles whose surface is hydrophobized. Hydrophobizing the surface of any of these fine powders has an excellent effect in terms of fluidity. In order to hydrophobize the surface, for example, a silicon compound generally known as a silane coupling agent or silylating agent can be brought into contact with and reacted with the particle surface.

  As the hydrophobizing agent, for example, chlorosilanes typically include trichlorosilane, methyldichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, ethyldichlorosilane, diethylchlorosilane, triethylchlorosilane, propyldichlorosilane, dipropyldichlorosilane, tripropylchlorosilane, Such as alkylchlorosilane, phenylchlorosilane and so on. Fluoroalkyl chlorosilanes and perfluoroalkyl chlorosilanes as the fluoro-substituted product. Typical examples of silylamines include hexamethyldisilazane, diethylaminotrimethylsilane, and diethylaminotrimethylsilane. Typical examples of silylamides include N, O-bistrimethylsilylacetamide, N-trimethylsilylacetamide, bistrimethylsilyltrifluoroacetamide, and the like. Further, as alkoxysilanes, methyltrialkoxysilane, dimethyldialkoxysilane, trimethylalkoxysilane, ethyldialkoxysilane, diethylalkoxysilane, triethylalkoxysilane, propyltrialkoxysilane, dipropyldialkoxysilane, tripropylalkoxysilane, Alkylchlorosilane, phenylalkoxysilane having a phenyl group, etc. Moreover, fluoroalkyl alkoxysilanes and perfluoroalkylalkoxysilanes as fluorine-substituted products. As silicone oil, dimethyl silicone oil and its derivatives. Fluorine substitution product. All compounds that are used as generally known hydrophobizing agents, such as disiloxane, hexamethyldisiloxane, and the like, can be used.

  The process cartridge of the present invention is characterized in that the developer of the present invention is used as a developer, and other configurations can be employed.

  Hereinafter, the present invention will be described specifically. The present invention is not limited to the embodiments exemplified herein.

Production Example 1
Put 20 parts of methoxymethylated polyamide (EF30T, manufactured by Nagase Chemtech Co., Ltd.), 1 part of citric acid, and 80 parts of methanol in a stirrable glass container equipped with a refluxer. A methoxymethylated polyamide methanol solution was prepared. Separately, 5 parts of aluminum triisopropoxide was dissolved in 30 parts of toluene and dissolved in the previous methanol solution with stirring.

Silanol group-containing methylsilicone resin (SiOH content 1 wt%, MW 15000) solid content concentration 20 wt% Solid solution amount equivalent to 20 parts of toluene solution is gradually added to the previous methanol solution, mixed and dissolved at 60 ° C for 3 hours. After refluxing, 80 parts of methanol and 80 parts of toluene were added and diluted to obtain a coating solution A. As a catalyst, 2 parts of a solid content of dibutyltin diacetate was added to the obtained liquid, and this liquid was applied to a ferrite core material with a fluid bed dryer to provide a resin film. The obtained powder was heat-dried at 210 ° C. for 2 hours to obtain carrier particles A having a film thickness of 0.6 μm. The thickness of the film was adjusted by the coating amount of the coating liquid A on the carrier core material.
As the carrier core material, ferrite particles having a weight average particle diameter of 35 μm and a magnetic moment of 82 emu / g at an applied magnetic field of 1000 Oe were used.

(1) The carrier resistance was measured by using a 4329A High Resistance Meter manufactured by Yokogawa Hewlett-Packard Co., Ltd., with a core material filled in a container having electrodes arranged in parallel at an interval of 2 mm, and the DC resistance at 500 V between the two electrodes.
(2) The magnetic moment was measured with an applied magnetic field of 1000 Oe using a multi-sample rotational magnetization measuring device REM-1-10 manufactured by Toei Kogyo Co., Ltd.
(3) The weight average particle diameter was the diameter (Dv) determined on the basis of weight measured with Microtrac.

This carrier resistance was measured as follows.
As shown in FIG. 1, a fluororesin cell 11 having parallel electrodes 12a and 12b having a gap of 2 mm and an electrode area of 100 mm ² is filled with a carrier 13, and applied voltages of 100 V and 500 V are applied between the two electrodes. The DC resistance is measured with a meter 4329A (manufactured by Yokogawa Hewlett-Packard Co., Ltd.), and the electrical resistivity LogR · Ωcm is calculated.
The electric resistance of this carrier was Log R14.4 Ωcm (50 V / mm) and 13.2 Ωcm (250 V / mm).

Production Example 2
Carrier B having a film thickness of 0.6 μm was obtained in the same manner except that the aluminum alkoxide used in Production Example 1 was changed from aluminum triisopropoxide to aluminum trisec butoxide. The electric resistance of this carrier was LogR14.2 Ωcm (50 V / mm) and 13.2 Ωcm (250 V / mm).

Production Example 3
In Production Example 1, the coating liquid A was transferred to a homogenizer, and 4 parts of carbon black (BP2000 manufactured by Cabot Specialty Chemicals Inc.) was added and dispersed for 30 minutes to prepare a coating liquid. Further, 80 parts of methanol and 80 parts of toluene were added to a diluted liquid, and 2 parts of solid content of dibutyltin diacetate was added, and this liquid was applied to a ferrite core material with a fluid bed dryer to provide a resin film. . The obtained powder was heat-dried at 210 ° C. for 2 hours to obtain carrier particles C having a film thickness of 0.6 μm. The electric resistance of this carrier was LogR 15.1 Ωcm (50 V / mm) and 14.8 Ωcm (250 V / mm).

Production Example 4
Carrier D was obtained in the same manner as in Production Example 3 except that 8 parts of carbon black (BP2000 manufactured by Cabot Specialty Chemicals Inc.) was used. The electric resistance of this carrier was Log R14.1 Ωcm (50 V / mm) and 12.8 Ωcm (250 V / mm).

Production Example 5
In Production Example 1, the coating liquid A was transferred to a homogenizer, 4 parts of carbon black (BP2000 manufactured by Cabot Specialty Chemicals Inc.) and 4 parts of alumina fine particles (particle size: 0.3 μm) were added and dispersed for 30 minutes. Created. Further, 80 parts of methanol and 80 parts of toluene were added to a diluted liquid, and 2 parts of solid content of dibutyltin diacetate was added, and this liquid was applied to a ferrite core material with a fluid bed dryer to provide a resin film. . The obtained powder was heat-dried at 210 ° C. for 2 hours to obtain carrier particles E having a film thickness of 0.6 μm. The electric resistance of this carrier was LogR 15.1 Ωcm (50 V / mm) and 12.7 Ωcm (250 V / mm).

Production Example 6
Production Example 5 A film was formed in the same manner except that the amount of alumina fine particles added was 8 parts to obtain carrier particles F having a film thickness of 0.6 μm. The electric resistance of this carrier was LogR 15.1 Ωcm (50 V / mm) and 13.8 Ωcm (250 V / mm).

Production Example 7
Carrier G was obtained in the same manner except that adipic acid was used instead of citric acid in Production Example 6. The electric resistance of this carrier was Log R 15.4 Ωcm (50 V / mm) and 14.0 Ωcm (250 V / mm).

Production Example 8
20 parts of methoxymethylated polyamide (EF30T manufactured by Nagase Chemtech Co., Ltd.), 1 part of citric acid, and 80 parts of methanol were added and heated to 60 ° C. and stirred in a water bath to prepare a methoxymethylated polyamide methanol solution. Separately, 5 parts of aluminum triisopropoxide was dissolved in 30 parts of toluene and dissolved in the previous methanol solution with stirring.

  Silanol group-containing methylsilicone resin (SiOH content 1 wt%, MW 15000) solid content 20 wt% solid solution equivalent to 20 parts of toluene solution was gradually added to the previous methanol solution, and further butoxylated hexamethylolmelamine toluene solution 4 parts of solid content was added, mixed and dissolved, and refluxed at 60 ° C. for 3 hours. Then, 80 parts of methanol and 80 parts of toluene were added and diluted to obtain a coating solution. This liquid was transferred to a homogenizer, 4 parts of carbon black (BP2000 manufactured by Cabot Specialty Chemicals Inc.) and 4 parts of alumina fine particles (particle size: 0.3 μm) were added and dispersed for 30 minutes to prepare a coating liquid. Further, 80 parts of methanol and 80 parts of toluene were added to the diluted liquid, and 2 parts of solid content of dibutyltin diacetate was added, and this liquid was applied to the ferrite core material with a fluid bed dryer to provide a resin film. . The obtained powder was heat-dried at 210 ° C. for 2 hours to obtain carrier particles H having a film thickness of 0.6 μm. The electrical resistance of this carrier was Log R 14.9 Ωcm (50 V / mm) and 13.2 Ωcm (250 V / mm).

Production Example 9
Carrier I was obtained in the same manner as in Production Example 8 except that butoxylated hexamethylol melamine was used as butoxylated tetramethylol benzoguanamine. The electric resistance of this carrier was Log R 14.8 Ωcm (50 V / mm) and 13.1 Ωcm (250 V / mm).

Production Example 10
12 parts of methoxymethylated polyamide (EF30T manufactured by Nagase Chemtech Co., Ltd.), 1 part of citric acid and 80 parts of methanol were added, and heated and stirred at 60 ° C. in a water bath to prepare a methoxymethylated polyamide methanol solution. Separately, 5 parts of aluminum triisopropoxide was dissolved in 30 parts of toluene and dissolved in the previous methanol solution with stirring.

  Silanol-containing methylsilicone resin (SiOH content 1 wt%, MW 15000) solid content concentration 20 wt% Solid solution amount 28 parts equivalent of toluene solution was gradually added to the previous methanol solution, and further mixed and dissolved at 60 ° C. 3 After refluxing for a period of time, 80 parts of methanol and 80 parts of toluene were added and diluted to obtain a coating solution. This liquid was transferred to a homogenizer, 4 parts of carbon black (BP2000 manufactured by Cabot Specialty Chemicals Inc.) and 4 parts of alumina fine particles (particle size: 0.3 μm) were added and dispersed for 30 minutes to prepare a coating liquid. Furthermore, 80 parts of methanol and 80 parts of toluene were added to the diluted liquid, and 1 part of γ-aminoethylaminopropitrimethoxysilane and 2 parts of solid content of dibutyltin diacetate were added. The resin film was provided by applying to the core material. The obtained powder was heat-dried at 210 ° C. for 2 hours to obtain carrier particles J having a film thickness of 0.6 μm. The electrical resistance of this carrier was Log R 14.8 Ωcm (50 V / mm) and 12.9 Ωcm (250 V / mm).

Production Example 11
Carrier K was obtained in the same manner except that no silicone resin was used in Production Example 1. The electric resistance of this carrier was Log R 113.6 Ωcm (50 V / mm) and 12.7 Ωcm (250 V / mm).

Production Example 12
Carrier particles were obtained without additional heating at 200 ° C. in Production Example 1. The electric resistance of the carrier L was LogR10.1 Ωcm (50 V / mm) and 8.2 Ωcm (250 V / mm).

Example 1
93 parts of carrier A created in Production Example 1 and 7 parts of black toner for IPSIO Color 8000 are mixed and used as a developer. This is loaded into IPSIO Color 8000, and the image area ratio is 12%. A continuous print test was conducted.
A small amount of developer was extracted at the start of the test and at the end of continuous printing, and the charge amount of the carrier in the developer was measured. Further, the background stain of the image at the end of printing 100,000 sheets and the charge amount of the developer were similarly evaluated.
The charge amount of the developer was determined based on a known blow-off method by collecting a small amount of developer from the sleeve of the developing device. The thickness of the carrier was determined by crushing the carrier and observing a cross-sectional image with a scanning electron microscope.

The stability of the charge amount with respect to the temperature and humidity environment was measured after the device after running was left in an environment of 40 ° C. and 90% Rh all day and night, and 1000 images were output.
The evaluation of the background stain was a four-level evaluation by visual evaluation.
The spent property was evaluated by separating the toner from the developer at the end of running, and measuring the transmittance of a solution obtained by dissolving 1 g of the obtained carrier in 10 g of a 1: 1 mixed solution of MEK and toluene. An average transmittance [%] of 320 nm to 700 nm was determined using a cell having an optical path length of 10 mm with a spectrophotometer.
The evaluation results are shown in Table 1. The symbols described in the table were ◎: very good, ○: good, Δ: slightly bad, x: bad (x is an unacceptable level).
The thickness of the carrier was determined by crushing the carrier and observing the cross section with a scanning electron microscope. The wear rate of the carrier was determined as follows.
The film thickness of the carrier before use is d1, the film thickness of the film after outputting 100,000 images is d2,
Film wear rate (%) = 100 × (d1−d2) / d1
It was.

Examples 2-10
In Example 1, the carriers B to J were used in place of the carrier A, respectively, and image evaluation was performed using the same developer. The results are also shown in the table.

Comparative Examples 1 and 2
Carriers K and L were also evaluated in the same manner as in Example 1. The results are also shown in the table.

Explanatory drawing of the measuring apparatus used for the measurement of the resistance value of a carrier in an Example.

Claims (17)

One or more alkoxyalkyls having a form having a film on the surface of magnetic fine powder, the film comprising (i) an N-alkoxyalkylated polyamide , and (ii) a silicone resin having at least a hydrolyzable group A carrier for developing an electrostatic latent image, comprising a cross-linked condensate formed from a coating liquid containing a resin capable of reacting with a nitrogen-containing resin and (iii) a metal alkoxide.   The carrier for developing an electrostatic latent image according to claim 1, wherein the polyamide of the nitrogen-containing resin is an N-methoxymethylated polyamide having a methoxylation rate of 20% to 70%.   2. The electrostatic latent image developing carrier according to claim 1, wherein the film is a cross-linked resin formed of a coating solution comprising a mixture of silicone containing silanol, N-methoxymethylated polyamide, and aluminum alkoxide.   4. The electrostatic latent image developing carrier according to claim 3, wherein the aluminum alkoxide is aluminum triisopropoxide.   4. The electrostatic latent image developing carrier according to claim 3, wherein the aluminum alkoxide is aluminum tri-sec-butoxide.   The carrier for electrostatic latent image development according to any one of claims 1 to 5, wherein the coating liquid contains a solid organic acid having a boiling point of 100 ° C or higher.   The carrier for electrostatic latent image development according to any one of claims 1 to 6, wherein the coating liquid contains methylol melamine.   The carrier for electrostatic latent image development according to any one of claims 1 to 6, wherein the coating liquid has methylol benzoguanamine.   The carrier for developing an electrostatic latent image according to any one of claims 1 to 8, wherein LogR at an applied electric field of 50 V / mm is 14 or more, and a resistance value at 250 V / mm is LogR16 or less.   The carrier for developing an electrostatic latent image according to claim 1, wherein the coating liquid contains a low-resistance substance.   The carrier for developing an electrostatic latent image according to claim 10, wherein the low-resistance substance is conductive carbon.   The carrier for developing an electrostatic latent image according to any one of claims 1 to 11, wherein the film has hard fine particles.   13. The electrostatic latent image developing carrier according to claim 12, wherein the hard fine particles of the film are a metal oxide of Si, Ti, or Al.   14. The electrostatic latent image developing carrier according to claim 13, wherein the content of the metal oxide particles in the coating is in the range of 5% to 70% of the coating weight.   The carrier for electrostatic latent image development according to any one of claims 1 to 14, wherein the coating liquid contains an aminosilane compound.   An electrostatic latent image developer comprising the electrostatic latent image developing carrier according to claim 1 and an electrostatic latent image developing toner.   A photosensitive member, a charging brush for charging the surface of the photosensitive member, and a developing unit for developing an electrostatic latent image formed on the surface of the photosensitive member using the electrostatic latent image developer according to claim 16; A process cartridge comprising a blade for wiping off the developer remaining on the surface of the photoreceptor.

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